Countercurrent chromatographic method previously reported (Z01 HL 01428-02) has been applied to preparative separation and purification of two synthetic polypeptides with 5 and 15 amino acids. The crude samples were purified with a two-phase solvent system composed of normal butanol, acetic acid, and water at a 4:1:5 volume ratio with a satisfactory level of recovery. The present method was proved to be well applicable to peptide samples which had poor solubility in the solvents commonly used in the conventional liquid chromatography.